1. Field of the Invention
The present invention relates to an airbag apparatus for a vehicle and, more particularly, to a vent structure configured for properly discharging inflating gas for an airbag cushion.
2. Description of the Related Art
An airbag protects a passenger from impact in the event of a vehicle accident by properly inflating an airbag cushion, thus reducing or preventing an injury. The inflating behavior of the airbag cushion plays a very important role in securing the safety of a passenger.
Particularly, the required inflating behavior of the airbag cushion should be such that the cushion inflates to provides rapid restraint of a passenger in an initial deploying stage. Subsequently, when the passenger comes into contact with the airbag cushion and a load is applied, inflating gas is properly discharged from the airbag cushion, thus allowing the passenger to be properly protected from impact.
Further, an airbag apparatus must meet requirements provided in various regulations, such as the North American Low Risk Deployment (LRD) regulation. According to the LRD regulation, inflating gas is required to be discharged through a vent hole, so as to minimize an injury to a child or a passenger near the airbag apparatus, even in the initial deploying stage of the airbag cushion. Hereinafter, performance for satisfying this LRD regulation will be referred to as “LRD performance”.
In order to satisfy the above-mentioned LRD performance, the vent hole of the airbag cushion should be open to emit some of the inflating gas, even in the initial deploying stage of the airbag cushion. However, in order to rapidly inflate the airbag cushion as described above, the vent hole should be closed in the initial deploying stage of the airbag cushion. Then, if the airbag cushion is fully inflated and a passenger starts to come into contact with the airbag cushion, the vent hole should be open to discharge inflating gas. As such, this is problematic in that, depending on the deploying process of the airbag cushion and the sitting condition of a passenger, it is not easy to properly open and close the vent hole at a proper time.
Korean Patent Laid-Open Publication No. 10-2005-00760440 is entitled “Airbag Cushion Having Variable Vent”.
However, this configuration is still problematic in that, depending on the deploying process of the airbag cushion and the sitting condition of a passenger, it is not easy to properly open or close the vent hole at a proper time.
The foregoing is intended merely to aid in the understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.